1. Field of the Invention
The present invention relates to an infrared decoy flare composition material for generating infrared radiation, which can advantageously be applied in an aerial infrared decoy flare.
In the military sector, missiles, such as air-to-air and surface-to-air guided missiles, which head for and pursue infrared (IR) radiation emitted by the target, chiefly in the range between 0.8 and 5 μm, with the aid of a seeker head sensitive to IR radiation, are used for combating air targets, such as, for example, jet aircraft, helicopters and transport machines. For defence against these missiles, flares which imitate the IR signature of the target are therefore used in order to deflect approaching guided missiles. Such flares can also be used in the pre-emptive release mode in order to complicate or even prevent the detection of targets by reducing the contrast of the scene.
Pyrotechnical infrared (IR) flares are typically used in military scenarios. Recently, however, civil aircraft, too, are being threatened by IR-guided missiles. Civil aircraft are at risk in particular from so-called MANPADS (Man Portable Air Defence Systems). Typical MANPADS constituting an asymmetrical threat to civil aircraft are, for example, the SA-7, SA-14, SA-16, SA-18 and the STINGER models Basic, POST and RMP.
In contrast to military aircraft, it is believed that civil aircraft are threatened only during takeoff and landing. A threat at flying altitude (>10 000 m) would also be conceivable, but this would require weapons systems which are not directly available to terrorists, at least in peaceful regions and furthermore cannot be used with the necessary camouflage, as is the case with MANPADS. The threat to civil aircraft during takeoff and landing is particularly precarious because, in contrast to more agile small military platforms, a passenger aircraft is not capable of making tactical manoeuvres during flight in order to escape a recognized threat. In addition, an aircraft taking off has a particularly intense IR signature, which facilitates lock-on of a seeker head.
Since the time window available for the protection of civil aircraft is therefore very limited, pyrotechnical IR flares are the preferred countermeasures in the combating of IR-controlled missiles.
2. Discussion of the Prior Art
Conventional IR flares for military applications are, however, characterized by certain features which complicate use for the scenario described above.
Thus, the pyrotechnical compositions of conventional IR flares burn with strong commission of both visible light and smoke. Since the ejection of flares and the visibility of this measure can lead to panic among the passengers on the ground and in the air, the visual signature of such flares should be as small as possible during the day and during the night. Furthermore, it is to be feared that ejected flares may fall to the ground while burning and may cause fires there. Typical charges have a combustion time of more than 3.5 seconds, so that flares ejected close to the ground can easily fall onto the runway or in the environment of the airport while still burning.
The disadvantages of known spectrally adapted active compositions for IR flares for use for detecting civil aircraft are therefore high luminous intensity in the visual range when metals are used as performance-enhancing additives, visible traces of smoke due to the formation of condensed products, and danger of fire on the ground due to a long duration of combustion of the pyrotechnic payload.